Deployment just keeps loading / spinning

Site name: https://transcendent-fenglisu-96a744.netlify.app/

When I deploy a static site to Netlify the interface says Uploading, and the spinner keeps spinning.
The total size of the deploy is 1.6mb including images and assets. No special JS frameworks.

Build log:
Loading. Yes that is what the log contains.

Build settings:
None. I’m deploying a flat HTML structure.

Ask Netlify:
Yes, I’ve tried Ask Netlify, but it didn’t give me any usable answers.

If you’re using the ‘drag and drop’ deployment see this support guide: